Modular multimorphic kinematic arm structure and pitch and yaw joint for same

Abstract

A multimorphic kinematic manipulator arm is provided with seven degrees of freedom and modular kinematic redundancy through identical pitch/yaw, shoulder, elbow and wrist joints and a wrist roll device at the wrist joint, which further provides to the manipulator arm an obstacle avoidance capability. The modular pitch/yaw joints are traction drive devices which provide backlash free operation with smooth torque transmission and enhanced rigidity. A dual input drive arrangement is provided for each joint resulting in a reduction of the load required to be assumed by each drive and providing selective pitch and yaw motions by control of the relative rotational directions of the input drive.

What is claimed is: 
     
       1. Modular multimorphic kinematic control arm means for selective manipulation of objects and the like comprising: support means for holding said arm means;   substantially identical shoulder, elbow and wrist joint means interconnected by link means, each of said joint means providing relative pitch and yaw motions between those of said link means joined thereby, and said shoulder joint being mounted on said support means via a said link means, each said joint means including,   traction driven output roller means mounted for rotation about orthogonal pitch and yaw axes in said link means, traction drive input means having first and second drive roller means for selectively rotating in like and opposite directions,   differential traction roller means in said link means engaging said output roller means for constraining said output roller means to rotate about said pitch and yaw axes, respectively, said differential traction roller means having first and second traction roll means independently rotatable about said pitch axis, engaged respectively, by said first and second drive roller means and being responsive thereto to rotate selectively, in like and opposite directions, and said traction drive input means engaging said differential traction roller means to selectively impart rotations thereto for controlling the rotation of said output roller means about said pitch and yaw axes,   said output roller means being mounted for rotation about said yaw axis and engaged at substantially diametrically opposed positions by said first and second traction roll means and is constrained to rotate about said yaw axis in response to opposite directions of rotation between said traction roll means and said drive roller means and to rotate about said pitch axis in response to like directions of rotation of said traction roll means and said drive roller means,   said shoulder, elbow and wrist joint means each providing two degrees of freedom to said control arm means;   said link means mounting said traction drive output means including a right angle mount for said traction drive output means, said right angle mount converting the orthogonal axes of rotation into pitch and yaw axes;   wrist roll means interconnected by a said link means to said wrist joint means and rotatable thereon for providing one additional degree of freedom to said control arm means in the total provision of seven degrees of freedom and obstacle avoidance capability in said control arm means; and   end effector means mounted on said wrist roll means for manipulating a said object and the like in response to movements of said control arm means.   
     
     
       2. The modulator multimorphic kinematic control arm means of claim 1, wherein said wrist roll means comprise traction drives. 
     
     
       3. Modular multimorphic kinematic control arm means for selective manipulation of objects and the like comprising: support means for holding said arm means;   substantially identical shoulder, elbow and wrist joint means interconnected by link means, each of said joint means providing relative pitch and yaw motions between those of said link means joined thereby, and said shoulder joint being mounted on said support means via a said link means;   said shoulder, elbow and wrist joint means each providing two degrees of freedom to said control arm means;   wrist roll means interconnected by a said link means to said wrist joint means and rotatable thereon for providing one additional degree of freedom to said control arm means in the total provision of seven degrees of freedom and obstacle avoidance capability in said control arm means; and   end effector means mounted on said wrist roll means for manipulating a said object and the like in response to movements of said control arm means;   wherein said shoulder, elbow and wrist joint means each connect a support side link means and a manipulator side link means for relative motion thereof and comprise:   output drive means mounted for rotation about orthogonal pitch and yaw axes in said link means, said link means including a right angle mount converting the orthogonal axes of rotational into pitch and yaw axes;   differential drive means in said link means engaging said output drive means for constraining said output drive means to rotate about said pitch and yaw axes, respectively; and   drive input means mounted in said support side link means and engaging said differential traction drive means to selectively impart rotations thereto for controlling the rotation of said output drive means about said pitch and yaw axes.   
     
     
       4. The modular multimorphic kinematic control arm means of claim 3, wherein said wrist roll means comprises a traction drive. 
     
     
       5. The modular multimorphic kinematic control arm means of claim 1, wherein said control arm means further includes position encoder means for providing an indication of the extent of each of said pitch and yaw motions in each of said joint means and the extent of rotation of said wrist roll means. 
     
     
       6. The modular multimorphic kinematic control arm means of claim 5, wherein, in each of said joint means there is a pitch axis and a yaw axis, and said position encoder means includes first and second rotary encoder means mounted on said pitch and yaw axes, respectively. 
     
     
       7. The modular multimorphic kinematic control arm means of claim 1, wherein: said control arm means further includes position encoder means for providing an indication of the extent of each of said pitch and yaw motions in each of said joint means and the extent of rotation of said wrist roll means; and   said wrist roll means comprises a traction drive.   
     
     
       8. The modular multimorphic kinematic control arm means of claim 7; wherein, in each of said joint means there is a pitch axis and a yaw axis, and said position encoder means includes first and second rotary encoder means mounted on said pitch and yaw axes, respectively. 
     
     
       9. The modular multimorphic kinematic control arm means of claim 1, wherein: said control arm means further includes position encoder means for providing an indication of the relative rotation of each said output roller means in each of said joint means on respective ones of said pitch and yaw axes and the extent of rotation of said wrist roll means.   
     
     
       10. The modular multimorphic kinematic control arm means of claim 3, wherein: said drive input means comprises first and second drive roller means for selectively rotary in like and opposite directions;   said differential drive means comprises first and second traction roll means independently rotatable about said pitch axis, engaged respectively, by said first and second drive roller means and being responsive thereto to rotate, selectively, in like and opposite direction; and   said output drive means is mounted for rotation about said yaw axis and engaged at substantially diametrically opposed positions by said first and second traction roll means and is constrained to rotate about said yaw axis in response to like directions of rotation between said drive roller means and to rotate about said pitch axis in response to opposite directions of rotation of said drive roller means.   
     
     
       11. The modular multimorphic kinematic control arm means of claim 3, wherein said drive input means comprises first and second rotary input means selectively rotatable in like and opposite directions and acting through said differential drive means to compel said output drive means to rotate about said pitch and yaw axes in response, respectively, to said like and opposite directions of rotation of said first and second rotary input means. 
     
     
       12. In a multimorphic kinematic control arm, means for providing six degrees of freedom and obstacle avoidance capability similar to that of a human arm comprising: first, second and third kinematically redundant pitch/yaw joint means simulating, respectively, shoulder, elbow and wrist joints of a human arm; and   link means for joining each said joint means to a related component of a said control arm; each said joint means including,   traction driven output means mounted for rotation about orthogonal axes mounted to one said link means;   differential traction means mounted in a different one of said link means engaging said output means for constraining said output means to rotate about orthogonal axes, respectively; and   traction drive input means engaging said differential traction means to selectively impart rotations thereto for controlling the rotation of said output means about said orthogonal axes;     said link mounting said traction drive output means includinga right angle mount for said traction drive output means, said right angle mount converting the orthogonal axes of rotation into pitch and yaw axes.   
     
     
       13. The means of claim 12 further comprising wrist roll means connected to said wrist joint for carrying an end effector means to manipulate a desired object and the like. 
     
     
       14. The invention defined in claim 13, wherein said joint means and said wrist roll means are traction drive means providing a substantially backlash free structure. 
     
     
       15. The invention defined in claim 13, wherein said wrist roll means comprises a traction drive. 
     
     
       16. The invention defined in claim 12, wherein: said traction drive input means comprises first and second drive roller means for selectively rotating in like and opposite directions;   said differential traction means comprises first and second traction roll means independently rotatable about said pitch axis, engaged respectively, by said first and second drive roller means and being responsive thereto to rotate, selectively, in like and opposite direction; and   said output means being roller means and being mounted for rotation about said yaw axis and engaged at substantially diametrically opposed positions by said first and second traction roll means and being constrained to rotate about said yaw axis in response to opposite direction of rotation between said traction means and said drive roller means and to rotate about said pitch axis in response to like directions of rotation of said drive roller means.   
     
     
       17. The invention defined in claim 16, wherein said wrist roll means comprises a traction drive. 
     
     
       18. The invention defined in claim 12, wherein said traction drive input means comprises first and second rotary input means selectively rotatable in like and opposite directions and acting through said differential traction means to compel said output means to rotate about said pitch and yaw axes in response, respectively, to said opposite and like directions of rotation of said first and second rotary input means. 
     
     
       19. The invention defined in claim 18, wherein said wrist roll means comprises a traction drive. 
     
     
       20. Traction drive pitch/yaw joint means for providing two degrees of freedom in a manipulation linkage comprising: first and seond rigid link means extending, respectively, into and out of said joint means for containing said joint means and assuming relative pitch and yaw positions to one another as constrained by said joint means;   servomotor means in said first link means for providing first and second rotary input drive motions, said input drive motions being selectively effected in like and opposite directions of rotation;   first and second traction drive input means connected with and driven by said servomotor means for assuming said first and second rotary input drive motions, respectively;   traction driven output roller means mounted in said second link means for rotation about orthogonal pitch and yaw axes in said joint means; and   differential traction roller means in said first link means engaging said output roller means and said first and second traction drive input means for constraining said output roller means to rotate about said pitch and yaw axes in response to opposite and like rotational directions of said input drive motions, respectively;   said second link including a right angle mount for said traction drive output means, said right angle mount converting the orthogonal axes of rotation into pitch and yaw axes;   said second link means being mounted in said joint means for like rotation about said pitch and yaw axes with said output roller means.   
     
     
       21. The traction drive pitch/yaw joint means of claim 20, wherein: said traction driven output roller means is journalled for rotation concentric with said yaw axis; and   said differential traction roller means is journalled for rotation concentric with said pitch axis.   
     
     
       22. The traction drive pitch/yaw joint means of claim 20, wherein: said differential traction roller means comprises first and second traction roll means independently journalled for rotation about said pitch axis, engaged, respectively, by said first and second traction drive input means and being responsive thereto to rotate, selectively, in like and opposite directions; and   said traction driven output roller means is journalled for rotation about said yaw axis and engaged at substantially diametrically opposed positions by said first and second traction roll means and is constrained thereby to rotate about said pitch/yaw axes in response to opposite directions and like directions rotation, respectively, of said first and second traction drive input means.   
     
     
       23. The means of claim 12 wherein said traction drive input means is mounted inboard of each joint.